• Proceedings of the IEEK Conference
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• 2002.07a
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• pp.293-296
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• 2002

This paper discusses a software reliability model for the distributed s-PCT algorithm fur remote sensing applications. The distributed algorithm is designed based on a Manager-Worker threading concept and goes further to use redundancy to achieve fault tolerance. The paper provides a status report on our progress in developing the reliability concept and applying it to create a model for the distributed s-PCT In particular, we are interested ill the algorithm performance versus reliability.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1719-1723
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• 2005

An automatic target sensing and triggering system for small fire arms is proposed. The system consists of an optical collector, an infrared ray sensor responsive to human body temperature, an electric actuator and a trigger mechanism. TRIZ methodologies are used to develop solutions to several contradictory problems. Experimental results on the system performance is compared with predictions.

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.434-438
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• 2000

In this paper the low cost sensorless control circuit for a PM synchronous motor without the mechanical rotor position sensors is presented. The sensorless control algorithm and position detection circuit for the sinusoidal current wave drive is more complex than that of the rectangular current wave drive. The proposed position sensing circuit is composed of an operational amplifier and several passive elements. The design procedures for getting the optimal parameters for the position sensing circuit are presented. The performance of the proposed algorithm is verified through the simulations and experiments.

• Journal of KSNVE
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• v.9 no.6
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• pp.1152-1156
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• 1999

In this study, a fiber optic air-backed mandrel hydrophone has been constructed and performance of acoustic signal detection has been measured. The hydrophone is based on a Mach-Zehnder interferometer with 35 m of sensing fiber. The sensitivity is measured up to -128 dB re rad/$\mu$ Pa in range from 1.4 kHz to5 kHz. A system with this design of hydrophone may be applied to detect low frequency underwater acoustic signals.

• Korean Journal of Remote Sensing
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• v.7 no.1
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• pp.13-27
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• 1991

DEM(digital elevation map) is a very useful information in various applications. In this paper, we have studied on the terrain matching algorithm using the DEM, which was proposed by Rodriguez and Aggarwal(1990) for an aircraft navigation system. We evaluated its performance using syntactic images. Cliff maps and critical points are used for the reduction of computation time and information size to be processed. The computer simulation shows that though the computational complexity is high, the technique is efficient even to noisy images.

• Applied Chemistry for Engineering
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• v.20 no.4
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• pp.370-374
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• 2009

A double-layer optical sensing membrane has been fabricated to measure the concentration of dissolved oxygen (DO) and pH value simultaneously. (tris(4,7-diphenyl-1,10-phenanthroline (Rudpp) ruthenium(II)) as a DO sensitive dye has been mixed in the methyl trimethoxy silane (MTMS) sol-gel solution and coated onto one well in a 24-well microtiter plate. On the DO-sensing layer the GA (3-glycidoxypropyl trimethoxy silane (GPTMS), 3-aminopropyl trimethoxy silane (APTMS)) sol-gel solution mixed with 8-hydroxypyrene-1,3,6-trisulfonic acid trisodium salt (HPTS) has been coated and used to measure pH values. The double-layer sensing membrane was affected by ionic strength and temperature. The double-layer sensing membrane for DO and pH has been applied to online monitor in microorganism cultivation processes and showed a good performance.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.10
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• pp.118-128
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• 2015

Compressive sensing (CS) has to face with two challenges of computational complexity reconstruction and low coding efficiency. As a solution, this paper presents a novel spatially scalable Kronecker two layer compressive sensing framework which facilitates reconstruction up to three spatial resolutions as well as much improved CS coding performance. We propose a dual-resolution sensing matrix based on the quincunx sampling grid which is applied to the base layer. This sensing matrix can provide a fast-preview of low resolution image at encoder side which is utilized for predictive coding. The enhancement layer is encoded as the residual measurement between the acquired measurement and predicted measurement data. The low resolution reconstruction is obtained from the base layer only while the high resolution image is jointly reconstructed using both two layers. Experimental results validate that the proposed scheme outperforms both conventional single layer and previous multi-resolution schemes especially at high bitrate like 2.0 bpp by 5.75dB and 5.05dB PSNR gain on average, respectively.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.10 no.2
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• pp.184-191
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• 2017

This paper presents cluster based hybrid spectrum sensing system for M2M services. For each cluster, secondary nodes within the transmission radius of the primary node use hard decision method through local spectrum sensing to determine whether the primary node exists. And the other secondary nodes and the secondary nodes having poor radio channel conditions judge the existence of the primary node through the soft decision method of the values obtained by performing the cooperative spectrum sensing. In the proposed hybrid spectrum sensing system, the performance according to the number of secondary nodes is analyzed with the conventional system over Rayleigh fading channel. As the number of cooperative sensing users increased to 2, 3 and 4, the cluster error probability decreased to 0.5608, 0.5252 and 0.4001 at SNR of -10[dB] respectively. Since the proposed system uses less overhead traffic, it is found that it is more effective in terms of frequency usage than the conventional system using soft decision-soft decision and soft decision-hard decision methods.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.9A
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• pp.859-867
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• 2010

In this paper, we consider a novel spectrum sensing system in which firstly, the fusion center (FC) senses and makes the own decision then if its sensing result is not useful for achieving the final decision, the local observations from the cognitive users (CUs) will be required. Moreover, in case that FC needs the results from CUs, we will choose only CU having the highest collected energy to send its local decision to FC. Based on this selecting method, the number of sensing bits can be reduced; hence, we can save the power and the bandwidth for reporting stage in the cognitive radio network (CRN). The mathematical analysis of the key metrics of the sensing schemes (probability of detection, false alarm, e.g.) will be investigated and confirmed by the Monte-Carlo simulation results to show the performance enhancement of the proposed schemes.

• Korean Journal of Materials Research
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• v.32 no.10
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• pp.435-441
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• 2022

We report the synthesis and gas sensing properties of bare and ZnO decorated TeO₂ nanowires (NWs). A catalyst assisted-vapor-liquid-solid (VLS) growth method was used to synthesize TeO₂ NWs and ZnO decoration was performed using an Au-catalyst assisted-VLS growth method followed by a subsequent heat treatment. Structural and morphological analyses using X-ray diffraction (XRD) and scanning/transmission electron microscopies, respectively, demonstrated the formation of bare and ZnO decorated TeO₂ NWs with desired phase and morphology. NO₂ gas sensing studies were performed at different temperatures ranging from 50 to 400 ℃ towards 50 ppm NO₂ gas. The results obtained showed that both sensors had their best optimal sensing temperature at 350 ℃, while ZnO decorated TeO₂ NWs sensor showed much better sensitivity towards NO₂ relative to a bare TeO₂ NWs gas sensor. The reason for the enhanced sensing performance of the ZnO decorated TeO₂ NWs sensor was attributed to the formation of ZnO (n)/ TeO₂ (p) heterojunctions and the high intrinsic gas sensing properties of ZnO.